As diagrammatically illustrated in FIG. 1, the typical multi-panel configured garage door 10 used for residential construction is comprised of a plurality of panels 11 (usually made of galvanized steel or fiberglass), which are hinged together at hinge joints 13, and are equipped with side wheels or rollers 15 that ride in a pair of guide tracks 17, 18 installed on opposite sides of the garage door opening 19. The tracks 17, 18 are usually anchored (bolted) to wall regions 21 and 22 of the garage adjacent to opening 19 and attached via brackets 25 to the ceiling 26. The door may be opened and closed either by hand or by way of an automated garage door translation device, usually mounted to the ceiling and attached to the topmost one of the panels 11.
It has been found that, when such a door is exposed to high velocity winds of a violent storm, such as a hurricane, the door panels 11 have a tendency to separate from the guide tracks 17, 18, due to continued flexing of the panels and fatigue of the tracks themselves, causing the side wheels 15 to become detached from the tracks 17, 18, so that the ends of the panels 11 become warped, allowing wind to enter the garage and literally rip or `peel` the door away from opening 19. Once the garage door has been blown out, the ceiling of the garage and adjacent structure are no longer protected from the extremely high velocity winds of the storm, and it is simply a matter of time before the roof blows off, causing the entire structure to be destroyed. Indeed, follow-up investigation to the widespread damage to residential buildings in south Florida by hurricane Andrew in 1992 has revealed that had garage doors been reinforced against such separation from the guide tracks, and not blown out, the full force of the hurricane would not have been able to enter many of the houses that were destroyed.
As a result of this investigation, home builders in coastal areas of south Florida are now required to provide `hurricane reinforcement` for their garage doors. Recommendations of how to accomplish this have usually involved the installation of (metal or wooden) girts that extend horizontally across each panel. Such girts are intended to stiffen the panels and prevent their oscillatory motion that leads to the destructive separation from the tracks.
Unfortunately, such stiffening panels add considerable weight to the door, requiring adjustment of both the lifting-coil spring and of the drive of the automated garage door translation mechanism. Moreover, even with such adjustment, the added weight of the girts, for which neither the door nor the automated translation mechanism were originally designed, leads to further wear and tear of the automatic door opener. Yet, even with such stiffeners, the fundamental problem they are intended to solve is not remedied, since they do not prevent torquing of the panels at the point of attachment of the door to the tracks.
More particularly, because the girts extend in the horizontal direction, they are parallel to joint lines between the panels and effectively provide axes of rotation about which the panels are torqued when subjected to the force of high velocity winds. They do not provide reinforcement or a barrier against separation along the lengths of the tracks.